import random
class Solution(object):

    def __init__(self, radius, x_center, y_center):
        """
        :type radius: float
        :type x_center: float
        :type y_center: float
        """
        self.r = radius
        self.x = x_center
        self.y = y_center


    def randPoint(self):
        """
        :rtype: List[float]
        """
        while True:
            rand_x = 2 * random.random() - 1
            rand_y = 2 * random.random() - 1
            if rand_x ** 2 + rand_y ** 2 <= 1:
                break
        x = self.r * rand_x + self.x
        y = self.r * rand_y + self.y
        return [x, y]
